Click HERE to read the story !!!

Could one call this an unintended ejaculation? Did they find any tumors in the pistol?

Well written article!
Peter.

Very well written article. Most of the time firearms novices make all kinds of factual errors when it come to writing about firearms and their operation.

The only thing I question is the assertion that the empty shell in the chamber proves that the safety was "on" when the pistol discharged. A 1911 and most any other similar pistols will fail to eject if there is insufficient restraint on the grip (ie: "limp wristing"). In the MRI, the pistol would be stuck firmly to the magnet but would more easily spun on it's axis in full recoil; it's highly likely that the pistol could have retained the empty shell after the discharge.

I have no idea what transpired, just questioning one one assertion that is less than a certainty.

I also enjoyed the objectivity of the writer and the technical accuracy. The other question that begs to be asked is if the impact was enough to to slam-fire the chambered round, was it enough (combined with the magnetic force) to move the safety to the "on" position?

I'm not 100% convinced that this could occur as stated, as a matter of fact I would almost state positively that it did not occur, at least as this version has it. This particular pistol has a number of safety features to prevent an accidental discharge. Further, does it make any sense that the magnetic field would only affect the firing pin block, and not the rest of the gun, which is also steel and would also be affected by the same magnetic field.

All this aside, there is NO way this pistol fired, with the thumb safety engaged thereby preventing the slide from cycling, with an empty shell remaining in the chamber, and yet the pistol remains cocked and locked (hammer back, safety engaged).

I fail to see how this is physically possible. Even if the pistol somehow managed to drop the hammer, bypassing all of the safety features (trigger, thumb safety, grip safety, firing pin block), and fire the round, the hammer would still remain down. The slide was unable to cycle and recock the hammer. additionally, if the hammer failed to drop, how did the pistol fire? The firing pin could not bypass the block and generate enough force to fire the pistol.

There are just too many contradictory issues contained within the incident, as presented.

Just my humble opinion.

h.c i'm with you on this one i watch rochester news but don't remember anything on this happening and everyone knows the press would have a field day of course i could of missed news that particular night

quote:

Originally posted by H.C.:
All this aside, there is NO way this pistol fired, with the thumb safety engaged thereby preventing the slide from cycling, with an empty shell remaining in the chamber, and yet the pistol remains cocked and locked (hammer back, safety engaged).

Good catch H.C., I didn't notice the cocked and locked photo purporting to show the pistol after it discharged. I'm with you, there's no way it happened as written.

quote:

Fig. 2C. —Photographs of 1991 A-1.45 caliber semiautomatic pistol (Colt's Manufacturing, Hartford, CT). Hammer, thumb safety, and grip safety of gun are shown. Gun is in cocked and locked position with hammer cocked and thumb safety turned on to prevent hammer from striking firing pin. This is condition in which gun was recovered from magnet.

Read it again... the claim is that the MRI unit magnetically lifted the firing pin block and that the impact on the muzzle was enough to drive the firing pin into the primer hard enough to ignite the primer. this explains how all the other safety's were bypassed. My assumption is the weapon is carried loaded, cocked and locked. The safety prevented any slide movement. It's all certainly logical.

I don't need to read it again, it is simply not possible. The firing pin spring would have prevented the firing pin from "Slam Firing" even if the magnetic field somehow only effected, or had some type of different effect on, the Firing Pin Block without effecting the rest of the pistol, which is also made of steel.

I know, perhaps the magnetic field also "magically" compressed the firing pin spring, at the same time it was lifting the firing pin block, and then the magnetic field effected the firing pin in a manner similar to a rail gun, forcing it forward at the necessary velocity to fire the pistol. Oh, it all makes sense now!

Sorry, I still don't buy it.

quote:

Originally posted by H.C.:
I don't need to read it again, it is simply not possible. The firing pin spring would have prevented the firing pin from "Slam Firing" even if the magnetic field somehow only effected, or had some type of different effect on, the Firing Pin Block without effecting the rest of the pistol, which is also made of steel.

I know, perhaps the magnetic field also "magically" compressed the firing pin spring, at the same time it was lifting the firing pin block, and then the magnetic field effected the firing pin in a manner similar to a rail gun, forcing it forward at the necessary velocity to fire the pistol. Oh, it all makes sense now!

Sorry, I still don't buy it.

The premise is that the firing pin block was moved by the magnet and the inertia of the gun being slammed into the MR unit was enough to overcome the firing pin spring tension and hit the primer. Explain why this wouldn't happen.

Time to call in the Myth Busters from TV.

I think what Collins is refering to is Inertia. Whats not listed is: 1) how far away the gun was from the Magnet, and 2) how fast was it traveling when it hit the Magnet.

If you watch all those front end collisions on TV, you will see most crash-test dummies still move forward even with a seat belt that is supposed to prevent that from happening.

The officer should have "unloaded the gun" when he was going to hand it to the Technician anyway. how many criminals was the officer going to encounter in there anyway....or was he going to have to shoot his way out of the machine?

Okay, I'm going to try to break this down a bit. The magnetic field of the machine grabs the weapon. Assuming the magnet within this machine is operating normally and is producing a balanced electromagnetic field. By this I mean that the magnet is emitting the field equally from all portions of the magnet. All right, now picture the field as a ball, equally affecting anything within the limits of this field. So a piece of steel located at 3 feet from the magnet, in any direction would have an identical magnetic attraction. According to this story, there was some type of errant magnetic field that attracted only the firing pin block, (although it is machined of steel, like the rest of the pistol) pulling the firing pin block in an opposing direction somewhere between 90 degrees and 180 degrees of the magnetic force drawing the rest of the pistol to the magnet, depending upon the pistol’s relative position and motion. Now I have been asked to clarify my statement, is the conflict in this story becoming any clearer?

Now, do you have an idea of where the pistol struck the magnet? Are there any red flags showing yet? According to the story, the pistol struck the left side of the Magnet bore, and according to the photo, striking the muzzle on an offset angle also on the left side. The bullet would have struck the magnet, then it may have ricocheted out the back, but that is not what occurred according to the story.

Would this be enough to pose doubt in the version as presented? Or would you need additional conflicting data?

Personally, you can believe whatever you want, I will believe that the facts don't match the story.




Fig. 2B. —Photographs of 1991 A-1.45 caliber semiautomatic pistol (Colt's Manufacturing, Hartford, CT). Muzzle of gun shows small amount of white paint (arrow) where gun impacted magnet.

quote:

All right, now picture the field as a ball, equally affecting anything within the limits of this field. So a piece of steel located at 3 feet from the magnet, in any direction would have an identical magnetic attraction.

Learn more about magnetism, learn more about an MRI and then we can chat... the assumption you make here is very incorrect.

I doubt we have much to "chat" about. I may not be able to correctly describe what I see and grasp from the story, I wouldn't be able to adequately type the correct and accurate procedures to allow you to know how I work a crime scene and "know" what to look for.

I also may not be able to accurately give a complete rundown of the theory of relativity, or quantum physics. I'm sure that someone of your "obvious" intelligence quotient would find any conversation with the "lower" life forms tedious and of no consequence.

As I previously stated, if you prefer to believe this story, as written, good for you.

BTW, I have some ocean front property in Kansas, want to buy it?

In order for you to understand how this happened, you'll first need to understand that magnetism is not a "ball, equally affecting anything within the limits of this field" If you don't want to or can't, there's no point in continuing.

http://en.wikipedia.org/wiki/Magnetism

http://en.wikipedia.org/wiki/Electromagnetism

The M1911 can fire when dropped! I have some 1st hand experience here.
see:
http://www.findarticles.com/p/articles/mi_m0BQY/is_8_51/ai_n14694932

This explains why Colt went to the firing pin block. Others have gone to lighter pins and heavier springs. The only problematic area is the firing pin block plunger being activated during the event.
C.G.B.

Yep the 1911 does not have a firing pin block. The 1991 does... and that's the source of the discourse.

quote:

Originally posted by cgbach:
The M1911 can fire when dropped! I have some 1st hand experience here.
see:
http://www.findarticles.com/p/articles/mi_m0BQY/is_8_51/ai_n14694932
This explains why Colt went to the firing pin block. Others have gone to lighter pins and heavier springs. The only problematic area is the firing pin block plunger being activated during the event.
C.G.B.

My understanding is the drop tests were done w/ the manual safety off & dropped onto the muzzle. There are findings that this does result in an AD at times. This is the first incident I have heard of where a 1911 fired when impacted on the muzzle w/ the manual safety engaged. I'm crying BS on this one & think maybe if the officer was lame enough to take his loaded 1911 into an MRI chamber, maybe he swiped the safety off accidently while removing it from his holster. Just a thought.

added to this did anyone verify that the Firing pin safety was actually present in the firearm?

MANY people REMOVE the firing pin block and the lever to actuate because of it's effect on the "Feel" of the trigger.

and a pre-"series 80" colt WILL fire if it is dropped onto it's muzzle from sufficient height (or more precisely impacting on it's muzzle with sufficient speed) to overcome the firing pin spring, which is NOT that stiff a spring.

You probably don't really want to hear that of the FIVE series-80 Colts that have passed through my hands that FOUR have needed to have their MISSING firing pin block components replaced.

I consider the idea that it's FAR more likely that the firing pin block was removed (and serrupticiously replaced before official examination) than the firing pin block being drawn out of the way AND HELD in that position by some magnetic or magical force for a subsequent impact


AD

both the 80's series and standard 1911's have a grip safety-- any evidence these were not working. For a pistol that has 3 (standard) or 4 (80's) safeties build in, I have some amazement that this has happened.

Please refer to Fig. 2C "This is condition in which gun was recovered from magnet."

Which shows hammer back in fully cocked position and safety on. But we never get to see the fired case that was still in the chamber.

Did the primer actually get indented by the firing pin? Or was the powder somehow ignited by the magnetic resonance? How did the hammer get back into the fully cocked position if the slide never retracted to do so after the cartridge fired?

I have worked in Radiology for the better part of 20 years....I find this difficult to swallow to be honest. This reminds me of a show I watched where a man was killed by a bullet fired by a Colt Gold Cup. I can't remember the details, but it was at a distance of about 100 yds. going through a wall, and hitting a guy while he was sitting in the club house. The final "answer" as to how this occurred was that it was a hand load in a "unsafely" altered gun..trigger job...that caused the gun to discharge twice instead of once, the second shot being at a "dangerous" angle. The kicker here is that it was a handload, loaded to approximately 1400 fps. That was the only way "physics" could prove that is what happened.
The point here is that they put in the 1400 fps number to prove they were right. I think that the "facts" were "discovered" so as to prove their theory. Not necessarily the truth, but it did prove what they thought happened.
It could have happened that way, but there is something not right here, IMHO.

I'd like to know, if you could fire a 1911 with the safety on, if that safety really would keep the slide from cycling...and if it did, what damage would any part of the safety suffer? I also wonder if the slide would ride over the safety forcing it down.

There is no doubt that the 1911 will fire went dropped on it's muzzle from a high enough height. That firing pin spring is in there to keep the pin from protruding through the firing pin hole, which if it did, would most likely prevent a fresh round from sliding up under the extractor. In other words to keep the firing pin in a rear postion at all times except when struck by the hammer...or dropped on it's muzzle...inertia.

quote:

Originally posted by onefunzr2:
Please refer to Fig. 2C "This is condition in which gun was recovered from magnet."

Which shows hammer back in fully cocked position and safety on. But we never get to see the fired case that was still in the chamber.

Did the primer actually get indented by the firing pin? Or was the powder somehow ignited by the magnetic resonance? How did the hammer get back into the fully cocked position if the slide never retracted to do so after the cartridge fired?

this question was covered, the scenario is that the firearm discharged WITHOUT the action of the hammer.

a 1911/1991 CAN be fired by dropping from sufficient height onto it's muzzle.
Even with the hammer physically removed.

Can the grip safety block the slide from moving?
The slide cannot reciprocate until it unlocks from the barrel shroud and that cannot happen until the slide retracts approx 3/16-1/4" the barrel and slide must be regarded as a unit.

Can the grip safety tolerate the shear force? probably once, repeatedly? probably not.

The slide CANNOT "cam" the safety out of the way.

and it isn't only the pivot pin that must shear off to allow the slide to move but the heavier sear/hammer block portion of the thumb safety

So the question is can some combination of impact and magnetic forces cause the firing
pin block to move out of the way so that the impact to the muzzle can fire the primer via inertia.

BTW, I am convinced absolutely that of all the people who have posted in this topic that there is doubt that ABOUT HALF of them have never handled a 1911 let alone actually understand how one is put together, as several of the counter questions asked could be EASILY answered if they had one in their hands and just LOOKED at it before asking their question.

I think the claimed scenario is extreemly unlikely, but things that are LESS unlikely happen all the time.

afterall, how many miniballs from civil war battlefields have been found mashed together nose-to-nose?

Quite a few actually...

what are the odds of two bullets impacting head on in midair? admittedly very small, but if you put enough bullets into the air at a given place and time the small chance swiftly becomes a certainty by sheer weight of numbers.

If you buy 100million lottery tickets your chances of winning approach certainty...

I can go on bu I think I've made my point.

Am I worried about getting hit by a stray bullet
from a series-80 1911 that is bouncing off an MRI machine? Nope.

I think it likely they could spend the next twenty years (working at it three shifts a day) tossing the very same 45 into the same MRI machine and fail to duplicate the accident.

I think it likely a "soft primer" was involved and until I personally examine the pistol
I will believe that the owner removed the series 80 firing pin block.

Because I find it hard to believe that there was sufficient magnetic forrce acting on the STAINLESS STEEL firing pin block to retract it gainst the spring.
There just isn't enough MASS for it to retract against it's spring.

AD

quote:

So the question is can some combination of impact and magnetic forces cause the firing
pin block to move out of the way so that the impact to the muzzle can fire the primer via inertia.

I think the preponderance of the evidence clearly says, "Yes", however unlikely.

But consider this:

I note (also, as it has been noted before) that the report does not refer to the existence or lack of a firing pin indentation on the primer. Existence of the indent would suggest the firing pin did move forward (whether under magnetic forces, intertial forces of a muzzle impact or inertial forces of the hammer "magically" falling and re-cocking itself without slide movememt) as described in the report.

But here is an alternative theory.

Has anyone considered that the primer could be heated by the (intense) magnetic flux. Heated sufficiently to ignite the primer compound without a firing pin impact? The muzzle impact might just be excess, misleading information. Not unusual in forensic and scientific investigations of all kinds.

Humbly (more or less) submitted for your consideration.

Larry (Lost Sheep)

nertial Discharge of the M1911 Pistol
By John De Armond

Others said:

#>> Ever dropped a 1911A1 on the muzzle? #>
#> Good point, bad example. M1911A1 is one of the safest pistols wrt accidental
#> discharge, with three distinct safety mechanisms.

#None of which does the least bit of good when you drop one muzzle first.
#The floating firing pin can slam forward with enough force to fire the
#gun when dropped on concrete, or other hard surface, muzzle first. The
#new Series 80 with the firing pin block brings the 1911 style into the
#late twentieth century by preventing this problem. Most other modern
#pistols don't suffer from this defect.

I've heard this bad rap against the 1911A1 (henceforth referred to as Colt) many times both in this group and in the magazines. That dropping a Colt on its muzzle being capable of igniting a primer goes contrary to my intuition. I finally decided to test this theory. I have done two tests. The first tries to scale the problem. The second involves actually dropping a gun.

Test #1 is to determine how much force is required to compress the firing pin spring sufficiently for the business end to protrude from the bolt face. Once this value is determined, the firing pin can be weighed and the number of Gs required to exert this force can be computed.

The test firearm is a box-stock Series 70 Colt Gold Cup. It was freshly cleaned and all oil film that could be wiped off was. The test setup is simple. I clamped the slide in a vice with the rear pointing up. A small drift was placed against the firing pin and Orhaus lab weights were stacked on the firing pin until the spring was compressed sufficiently that the firing pin barely protruded from the bolt face. Then the drift was weighed on an Orhaus triple beam balance and the weight was added to the lab weights weight. Finally the firing pin was weighed on the same balance. Results:

Firing pin weight: 4.4 grams

Total weight required: 506 grams

Computed G force: 506/4.4 = 115 G


Note that this is the minimum force needed to make the firing pin barely protrude. This does not account for the force required to actually fire the primer. I tried to get a rough idea of what this force is by putting a primer that had been inserted in a case, placed the casing in a barrel and slide assembly minus the firing pin spring and then placed weight on the firing pin sufficient to cause the first dent in the primer. The primer was a Winchester large magnum pistol primer. I ran out of weights at 4 kg. No dent. That would be equivalent to about 1000 G of force. If anyone has factory specs on the required primer force, I'd love to have them.

Keep in mind, that these static tests do NOT account for the pretty significant aerodynamic counterforce involved with a firing pin propelled at sufficient velocity to fire the primer. Once the firing pin protrudes into the bolt hole, the pin and bolt forms a fairly tight cylinder with air trapped inside. This damps the pin and absorbs some portion of the force.

Based on these results, I got brave and proceeded on to the next test. An old slide, bushing, barrel and the Gold Cup firing pin and spring were assembled. A case with a live primer was chambered and the whole assembly was duct taped to make sure the barrel stayed in battery. Then the whole assembly was dropped muzzle first down various lengths of pipe onto my asphalt driveway. The pipe guided the assembly and made sure the muzzle remained pointed straight down.

The longest pipe I could find was 15 feet long. Several drops from this altitude failed to fire the primer. The primer was marked but not enough to call it a dent. I did one more drop with the firing pin spring removed. The primer was dented pretty severely but it did NOT detonate. I suspect that with several drops, one or more might fire the primer. I got bored and my slide was getting boogered up so I stopped with the one drop.

Based on these tests, I feel confident in saying that there just ain't no way dropping a Colt on its muzzle is going to inertially discharge the thing. I could believe that dropping a tinkered-with or hot-rodded gun could cause the sear to break, dropping the hammer and firing the gun. I would believe that people who cause ADs would claim that dropping the gun caused it 'cuz they were embarrassed. But I would have major doubts that dropping a gun even with the firing pin spring removed would do anything.

Methinks the Colt has gotten a very bad rap and that the firing pin blocking gimmick placed on Series 80 and subsequent Colts is just that - a lawyer gimmick. Looks to me like the original Colt designers did their homework.

-- John De Armond,

First, I hope no one is proposing we redesign a fine weapon so that it will be "MRI" safe!

Second, I was told when I had an MRI a couple of years ago that women's hairpins that become dislodged and pulled into the MRI will actually accelerate to the speed of sound prior to hitting the magnet. The force involved here is very significant.

Third, it appears the pistol was pulled in and hit on the forward edge of its frame/barrel. If it stopped, the firing pin and other associated mechanisms kept on truckin'. Even if the firing pin were not magnetic, its inertia could result in the discharge.

Fourth, I would have to see a schematic and explanation of the firing pin block, assuming it has not been removed, to be able to say whether it would stop the firing pin from moving under the circumstances described in this incident. Kudude

quote:

Originally posted by kudude:
First, I hope no one is proposing we redesign a fine weapon so that it will be "MRI" safe!

Second, I was told when I had an MRI a couple of years ago that women's hairpins that become dislodged and pulled into the MRI will actually accelerate to the speed of sound prior to hitting the magnet. The force involved here is very significant.

Third, it appears the pistol was pulled in and hit on the forward edge of its frame/barrel. If it stopped, the firing pin and other associated mechanisms kept on truckin'. Even if the firing pin were not magnetic, its inertia could result in the discharge.

Fourth, I would have to see a schematic and explanation of the firing pin block, assuming it has not been removed, to be able to say whether it would stop the firing pin from moving under the circumstances described in this incident. Kudude

Here you go if these work.

After posting the alternative theory of an explanation of the accidental discharge of the .45 in the MRI machine (Enough heat to ignite the primer or powder being generated by magnetically induced eddy currents in the cartridge or primer cup), I thought of another possibility.

I should give some credit to onefunzr2 who observed "... But we never get to see the fired case that was still in the chamber. Did the primer actually get indented by the firing pin? Or was the powder somehow ignited by the magnetic resonance?"

In the intense magnetic flux of the MRI chamber, could a spark be generated between the primer cup and the primer anvil (separated by only a thin layer of primer compound)? If the flux was enough (as Sgt Benwitz-the Rochester PD Firearms guy- suggested) to affect the structural metal of the gun, it might penetrate to the primer.

Have you ever put two metal objects close to each other, but not quite touching in a microwave? Quite a lot of sparking goes on.

A spark inside the primer compound would definitely set off a cartridge if that occurred.

Now, I know that a space fully enclosed in electrically conducting material (like a gun chamber) SHOULD block the magnetic flux (much as a foil tent protects turkey legs in a microwave oven), but if the flux were strong enough, it might be able to penetrate to the inside of the gun. The question I now have is, "Why didn't any other rounds in the magazine go off?" Maybe the magazine was not in the gun? Speculation.

By the way, I believe this is not a hoax or urban myth. The American Journal of Roentgenology is a real publication and this article came out in Volume 178, Issue 5 in May of 2002 describing the analysis of events that occurred in Brighton, New York on September 13, 2000.

I pulled these two partial articles from the web site of the Rochester Democrat and Chronicle.

http://nl.newsbank.com/nl-search/we/Archives?s_site=dem...B%2CE&p_text_date-0=

1. DAILY DIGEST
September 15, 2000 •• 406 words •• ID: roc2000091510092197
Test too risky for magnet-pulled gun It would be too risky to test the gun yanked out of an off-duty city police officer's hand by a heavy-duty magnet this week, a firearms expert said yesterday. The magnet, used for magnetic resonance imaging tests, might have changed the molecular structure of the .45-caliber handgun, said Sgt. William Benwitz, who runs the firearms training unit at the Scottsville Road training academy. "Until we send this gun back to the


2. DAILY DIGEST
September 14, 2000 •• 347 words •• ID: roc2000091410192034
MRI `disarms' police officer Just call it a really magnetic attraction. An off-duty Rochester police officer went to Borg Imaging at 200 White Spruce Blvd., Brighton, yesterday for a magnetic resonance imaging test. The officer asked an office worker about his handgun and, according to Brighton police, was told to keep it with him. But as soon as the officer entered the room holding MRI equipment, the heavy-duty magnet yanked the gun from his hand. Even the bullets

If I wanted more of the articles, I would have had to have broken out my credit card with no promise that a few more paragrpahs would reveal more evidence, so I didn't.

I Googled "William Benwitz" and believe he is still employed by the Rochester PD, so if anyone wanted to call or email to ask if he inspected the back of the primer for firing pin marks... He might respond better to a fellow policeman (if there are anyh attending this thread) than me, just an idle curiosity seeker.

Larry (Lost Sheep)

Say the MRI machine magnetically induced eddy currents in the cartridge or primer cup. Why didn't any of the cartridges in the magazine go off?

quote:

Originally posted by H.C.:
I don't need to read it again, it is simply not possible. The firing pin spring would have prevented the firing pin from "Slam Firing" even if the magnetic field somehow only effected, or had some type of different effect on, the Firing Pin Block without effecting the rest of the pistol, which is also made of steel.

I know, perhaps the magnetic field also "magically" compressed the firing pin spring, at the same time it was lifting the firing pin block, and then the magnetic field effected the firing pin in a manner similar to a rail gun, forcing it forward at the necessary velocity to fire the pistol. Oh, it all makes sense now!

Sorry, I still don't buy it.

H.C.,

I respectfully disagree. Pre-series 80 Colts are known to be able to "slam-fire" with a blow on the muzzle. The firing pin block prevents that, but only if it is in the DOWN position. If this particular gun struck the rear top of the slide, the firing pin block would, inertially, bump up into its recess, thereby clearing the way for a simultaneous smack on the muzzle to inertially drive the Colt's inertial firing pin into the primer.

Yes it is possible, however improbable. As Conan-Doyle said through his character, Sherlock Holmes, "Once you have eliminated the impossible, what remains, however improbable, must be true." I don't remember the name of the book, sorry.

Take a look at my next post describing the 1994 experiments where a Browning was induced to drop its hammer (on an empty chamber) 6 out of 6 times, and a Taurus 92, 2 out of 6 times. Not exactly the same situation, but 1.5 Teslas generates a LOT of force.

Larry (Lost Sheep)

For your consideration: This experiment is not precisely analogous to the events in the imaging center with the Colt 45, but nteresting and illuminating, nonetheless.

In an article in the publication Radiology in 1994, 193:875-876 indexed under terms "Firearms" and "Magnetic Resonance (MR), safey" and entitled "Firearm Safety in the MR Imaging Environment" written by Emanual Kanal, MD and Ali Shaibani, MD six handguns were tested to see if they could be induced to fire by being near or in the bore of a 1.5 Tesla MRI machine. That is the same strength of the machine we have been discussing here.

These were the six guns.

Smith & Wesson Model 66 2.5" .357 Magnum revolver
North American Arms 22 Magnum mini-revolver
Taurus PT-92C 9mm Semi-auto
Glock Model 19 9mm Semi-auto
Browning BDA-380 380ACP Semi-auto
Star Model M-43 Firestar 9mm semi-auto

They were inserted several times in varying stages of readiness to fire (unloaded) to determine if the hammer would drop on the firing pin. As I read the article, the testing did not exhaust all the possible orientations, but did include being withdrawn from the machine barrel first and being inserted and withdrawn from the machine oriented such that the magnetic forces would likely move the manual safety (on the guns that had them) to the off position. Again, where the gun had a hammer able to be cocked, the experiments were repeated in the fully cocked position.

None of the guns "fired" (on an empty chamber) when they were uncocked and introduced and withdrawn from the magnet room or bore of the MRI machine. Similarly none of the guns with manual safeties went "off safe". Also, when fully cocked (and off-safe for those with manual safeties) the Smith, Glock, Star and North American Arms guns did not "fire". However, the Taurus dropped the hammer in two out of the six times the gun was withdrawn muzzle first from the MRI's bore and the Browning "fired" 6 out of 6 times.

Moreover, "The trigger of the Browning handgun was repeatedly seen to begin to be 'depressed,' or pulled, toward the firing position when the gun was more than 2 feet away from the bore opening. In each case, the cause of firing was not hammer motion but was ferromagnetic attraction of the imaging system on the trigger itself."

Clearly, magnetic flux in the realm of 1.5 Teslas can move guns or parts of guns.

The Colt .45 design was not tested by these researchers, but then they were testing a slow-moving gun in the magnetic field. Add high-speed momentum to the experiment, where not only the firing pin might slam-fire on the primer, but the firing pin block might slam upward against its (weak) spring pressure, or be drawn upward by magnetic forces on the block or on the lever that moves the block (normally by action of the trigger) and the way is clear (in both senses of the phrase) for the firing pin to hit the primer just as a series 70 and earlier models are known to do under the right circumstances. That is, if you lift the firing pin block by magnetism or by momentum at the same time the pistol strikes its muzzle on the side of the bore of the MRI machine, there is nothing to prevent a slam-fire, just as pre- '80 series Colts were capable of having.

I still want to know if there was a firing pin dent on the primer. I am suspecting more and more that there is. However I still also suspect that the magnetic flux either by heat could "cook off" or by spark could detonate the priming compound.

Larry (Lost Sheep)

Now to put my foot back in my mouth

I have owned a couple of 1911's, an original 1911 and a Gold Cup.
I have also had a few MRI's.
Whilst the firing pin block may have been removed, it would be very interesting to find out about the primer state of the fired round. When I have had MRI's I have been asked whether I have any metal like pins, plates (I didn't then!) and also whether I might have metal in my eyes from grinding etc. Once answering yes to the latter I had to have an eye x-ray to determine if I had even a speck of metal in my eye(s). I thought maybe the MRI unit would pull the metal out with force and that's why they checked. No. It was because the MRI unit would cause the metal fragment to become extremely hot and cause significant damage.
I don't know enough about the MRI machine as to whether this would only occur when fully functioning, although it pulled the gun with force from 3 feet away and the article mentioned it was energised. And if so why not cook off the other rounds, assuming the magazine was still in the gun, which it looks like the gun was still holstered from the photo of it attached to the MRI unit? Perhaps some focussing of magnetic force in the chamber, bimetal effect etc. What was the primer metal? Could a spark jump from the slide to the primer? Aluminium creates a hot spark, is it used in primers?
I guess until we find out about that primer we are all speculating. But it is an interesting topic and discussion.

Primers are made of a brass or copper alloy. Some are plated on the outside with what looks like chrome. They aren't magnetic nor do they rust.

I would agree that if the magnetic flux ignited the chambered round, most likely it would also ignite those in the magazine.

No matter the cause, it was an oversight NOT to have included any text or photo of the actual condition of the fired case, either still in the chamber or ejected and found laying on the floor. And if the latter, was a fresh round loaded into the chamber?

I certainly couldn't concur with the stated explanation without seeing the fired case.

quote:

Originally posted by starmetal:
Primers are made of a brass or copper alloy. Some are plated on the outside with what looks like chrome. They aren't magnetic nor do they rust.

Actually primers and their anvil are almost always made of plated steel.
You can pick them up with a magnet.

Copper is "bad" if brought onto contact with some priming compositions....

AD

I don't know what kind of primers you've been using because mine aren't magnetic. And I said alloys, not pure copper. How many primers do you see stuck to the magnet in the attached picture?

Get your facts right if you're going to post on this subject pleas.

quote:

Originally posted by onefunzr2:
I would agree that if the magnetic flux ignited the chambered round, most likely it would also ignite those in the magazine.

No matter the cause, it was an oversight NOT to have included any text or photo of the actual condition of the fired case, either still in the chamber or ejected and found laying on the floor. And if the latter, was a fresh round loaded into the chamber?

I certainly couldn't concur with the stated explanation without seeing the fired case.

No, no, no.

Clearly stated in the original article (link is in the first post), the sole, fired case was found in the chamber with the manual safety on and the hammer back at full cock.

The article did not describe the condition of the primer in the fired case, not did it mention anythng about the magazine or any other rounds.

Certainly there was no fired case "ejected and found laying on the floor".

However, I did take my own advice and re-read the article. Near the end of the "Case Report" section of the report this conclusion is revealed:

The gun likely discharged as a result of the effect of the magnetic field on the firing pin block. The firing pin block was probably drawn into its uppermost position by force of the magnetic field. The firing pin block has to overcome only light pressure from a relatively small spring to release the firing pin. The pistol was likely drawn into the magnetic field so that the muzzle struck the magnet's bore first. With the firing pin allowed to move freely in its channel, the force of the impact on the muzzle end was sufficient to cause the firing pin to overcome its spring pressure and move forward to strike the primer of the chambered round.

This account explains how the weapon discharged when the thumb safety was engaged.

end of quote

The presence of an indentation on the back of the primer would virtually guarantee that conclusion is the correct one.

Larry (Lost Sheep)

quote:

Originally posted by starmetal:
I don't know what kind of primers you've been using because mine aren't magnetic. And I said alloys, not pure copper. How many primers do you see stuck to the magnet in the attached picture?

Get your facts right if you're going to post on this subject pleas.

Whether the primers, the anvils inside them or both are ferromagnetic or completely magnetically inert is beside the point. Magnetic flux affects nonmagnetic metals, too.

If a changing magnetic field surrounds a conducting material or that material moves through a static magnetic field or both, (the material can be magnetic or non-magnetic, doesn't matter) eddy currents are set up. That's why your car can generate voltage in COPPER WIRES (steel wires work, too, but copper has less resistance, so we use copper). Those currents can generate a lot of heat, too, by the way. And the electromagnetic forces from those eddy currents generate force, too. How many of you reloaders out there have counterbalance scales with MAGNETIC DAMPING of the counterweight arm? My little RCBS 505 does. The damper is a 1.5" by 3" (approximate) thin copper plate that moves up and down in a magnetic flux field (simply the poles of a permanent magnet).

So whether your primers are made of a magnetic metal or a nonmagnetic, makes little difference.

Larry (Lost Sheep)